beta-dimethylamino-ethyl rho-halobenzhydryl ethers and their salts



inorganic or organic acids.

Patented a. 31, 1950 p-DIMETHYLAMINO-ETHYL p-HALOBENZ- HYDRYL ETHERS AND"THEIR'SALTS George ltieveschl, Grosse Pointe .Woods, Mich., assignor to Parke, I) avis & Company, Detroit, Mich,, a corporation of Michigan No Drawing. Application June '16, 1948, Serial No. 33,432

This invention relates to a specific class of sub- 9 claims. (o1. zed-567.61

stituted fi-dialkylaminoalkylbenzhydryl ethers and their salts and to methods for obtaining the same. More particu1ar1y,.the invention relate to B-dimethylaminoethyl 'p-halobenzhydryl ethers and their salts. The free base ofl the, amino ethers of this invention have the formula,

- CHOCHiCHiN Q The products of the present invention may be obtained as a free base having the formula given I where X is a halogen atom that is; 'fiu'orine, "spasms? 0011mm gpas'ms'jand chlorine, bromine or iodine atoms above or as an acid addition salt of the base with Some examples of the salts which may be prepared by the methods hereinafter described are the hydrochloride, 'hybrobromide, hydroiodide, sulfate, phosphate, acetate, citrate, oxalate, succinate, tartrate, benzoate, phthalate, malate, oleate and the like. In its broader aspects the inventionincludes the quaternary ammonium, as'well as the acid addition salts of the S-dimethylaminoethyl p-halobenzhydryl ethers. These quaternary ammonium salts are prepared by reactingan alkylor aralkyl halide, a dialkyl sulfate or'an alkyl aryl sulfon'ate with the free base of the ,B-dimethylamihoe'thyl p-halobenzhydryl ether. The quaternary "amg; fI'he inventionfisillustrated. by the 15 I t. r v v j :The free bases, the acid addition salts and the quaternary ammonium salts of the p -dimethylaminoethyl p-halobenzhydryl ethers of the invention are powerful antihistamine agents. They are also useful in preventin smooth muscle spasmsfjinduQed-by histamine, acetyl choli e' or barium chloride. 'These 'new products ma fbe 1 administeredto'humans orally; parenterally; rec- I ,t ally'oifas a vapor. or mist.- They find particular V v v H. fdition's '(asthma, urticaria, histamine. 1

l-and naphylactic shock) and smoo h ,use lnihumans for the treatment ofalle examples:

Example *1;--5-DimethyZaminocthyl p-fluoro- I -benzhydryl ether i 2 5 cc. of acetyl bromide is slowly to {A 'g of p fluorobenzhydrolj.dissolvedin 5O ccl'of i the acetic acid ,whichis formeddistilled off under monium halides can'also be prepared by. the rebinding agent or with or without a solvent, An-

other method for preparingthesecompounds consists in reacting an alkali metal salt of ,a-p'-halo-' benzhydryl with a B-dimethylaminoethylhalide and an alkali metal salt of afi-dimethylaminoethanol reacted with a p-halobenzhydryl halide. A furthenmethod of preparation consists in reaction of a ,B-haloet-hyl p-halobnzhydryLether I So'mespecific exred ,cedfgpressure to obtain'the' desired p-fluordxylene After the addition has been completed the reaction .mixture is refluxed for about, four I hours, cooledand treatedwith about loflfccli'of water.

jcarded The etherextractjis combinedwith the gorganic layer, the combined extract washe d'with water and then extracted, with severalj portions .of dilute hydrochloric acid (about 20 cc, ofcon- @jcentratedghydrochloricacid in 50 ,cc, of water).

or, if desired, the reactants may be interchanged acting a [3-haloethyl-p halobenzhydryl ether with dimethylamine.

Themlayers are separated, the aqueous layer.extractedonce with ether and then, dis- Th 'acidio extract-is clarified, by extracting it once with ether, the-ether'discardedj-andtlie aqueous s olution made alkaline with 40 or sodium XQeS, qfr-dlfy'hyqrpgen chloride dissolved in l time: 'a d' ft solution added slowlyto a 're benzhydryl ether may be isolated from the above reaction mixture as the free base rather than as the hydrochloride salt. This is acoomplishedlby evaporating the ether from the dry ether extract containingthe crude free base of fl-dimethyle aminoethyl p-fluorobenzhydryl ether and distilling the residue under reduced pressure. (about above .in the case of the hydrochloride salt, or

from the purified free base. When starting with the purified free base, one dissolves it in an alcohol, ether, benzene or the like and then adds the solution to, or to the solution, the acid corresponding to the desired salt. For example, the

oxalatesalt may be prepared as follows:

g. of the free base of ,B-dimethylaminomethyl p-fluorobenzhydryl ether is dissolved 'in a small amount of isopropanol and the resulting solution added with stirring tofa warmisopropanol solution containing one equivalent of .oxalid acid .monohydrate. The white, crystalline acid oxalate salt of fi-dimethyl-aminoethyl p-fiuorobenzhydrylether which separates on cooling is collected and purified by recrystallization from isopropanol.

The hydrobromide salt can be prepared by dis 1'.

solving 10 g. of the free base 'of fi-dimethylaminoethyl p-fluorobenzhydryl ether, in anhydrous ether and'treating the solution with an excess of dry, gaseous hydrogen bromide. The white p (p Fluorobenzhydryloxy)ethyl trimethylammonium iodide may be prepared by dissolving 10g. of eedimethylaminoethyl p-fiuorobenzhydryl ether in aboutw'lQcc. of acetone and adding 52g. of methyl iodide dissolved in 20 cc. of acetone slowly to the solution with stirring. The resultant .mixture is allowed to stand about itenihours, the productcollected and purifie dbyj recrystallization from ethanol.

6.8 g. of methyl ,p-toluenesulfonate added slowly to 10g.ofe-dimethylaminoethyl p-;fluoro- .benzhydryl ether in 50 cc. of benzene. After the addition has been completed the mixture is allowed tostand for about four or five hours, diluted with ether and the crystalline product removed .by filtration. The crude ,e-ip-fluorobenzhydryl- 25 cc. of acetyl bromide added cautiously to 43.7 g. of p-chlorobenzhydrol in 50 cc. of hen- -,Dimethylaminoethyli plchlorozene and the resulting mixture heated under reflux for one-half hour. The benzene, excess acetyl bromide and acetic acid are removed by distillation in'vacu'oto obtain the desired p-chloro- 5 'benzhydryl bromide.

The p-chlorobenzhydry bromide prepared above is dissolved in about 20 cc. of xylene and the solution added slowly to a refluxing solution of 40 cc. of b-dimethylaminoethanol in 50 :cc. of xylene. After the addition has been completed the reaction mixture is refluxed about four hours, cooled and treated with about 100 cc. of water. The layers are separated, the aqueous layer extracted .once with ether and then discarded. The ether extract is combined with the organic layer, the combined extract washed with water and then extracted with several portions of dilute hydrochloric acid. The acidic extract is clarified by extracting itonce with ether, the other discarded and the aqueous solution made alkaline with 40 or 50% sodium hydroxide solution. The free base ofp-dimethylaminoethyl p-chlorobenzhydryl other which separates is extracted from th aqueous solution with several portions of ether, th ether'extracts washed with water and then dried over anhydrous potassium carbonate. The drying agent is removed by filtration and the filtrate treated with anexcess Decr hydrogen chloridedissolved in isopropanol. 'The hydro chloride salt of edirnethylaminoethyl p-chloro- .henzhydryl ether which separates is collectedand purified by recrystallization from isopropanolxether mixture; M. P. :134-6 C.

than the hydrochloride salt in the above procedure. This is carried out by evaporating the other from the dry ether extract containing the -B-dimethylarninoethyl p-chlorobenzhydryl ether. The free base so obtained can be purified either :by distillation orvia one of its acid addition salts followed by neutralization.

4.5 g. :of benzyl chloride is added to 1i?- g. of 8-dimethylaminoethyl p-chlorobenzhydryl ether in 50 :cc. of benzene and the mixture warmed on a steam bath :for eight hours. The mixture is cooled, .the I crystalline fi-(p-chlorobenzhydryl- .oxy) ethyl. dimethylbenzylammonium :chloride collected are purified by recrystallization from absolute ethanol-ethyl acetate mixture. 5Q 4.4g. of dimethyl sulfate is added slowly to solution of 10 g. of fi-dimethylarninoethyl :p- -chlorobenzhydryl ether in cc. of ether and after the :addition :has been completed the mixture allowed to stand for about four hours; The crystalline 8-1p-chlorobenzhydryloxy) ethyl trimethylammonium methosulfate iscollected and purified by crystallization from absolute ethanolethe'r mixture. I

i .Emcmple ,3.,8-,Dimethylamiwoethyl p-bromobenzhydryl ether 125cc. of acetyl bromide is added slowly to a solution'of 26.3 g. .of p-bromobenzhydrol in: about 30 cc. of benzene. After the addition has been 'completed the reaction mixture is refluxed for one hour and then the benzene, excess acetyl bromide and acetic acid removed by distillation in vacuo to obtainthe desired pbromobenzhydryl bromide. I The p-bromobenzhydryl bromide preparedas If desired-tliejfree base maybe isolated rather described above is dissolved in about 3 5 of xylene and the solution added sjlowly'ltjo a refiuxing solution of ccI or'b-dimethylam inm ethanol in cc. of xylene. After the addition has been completed the reaction mixture is refluxed for about. threetofour, hours, cooled and treated with about 50 cc. of water. The layers' anhydrous potassium carbonate and the drying agent removed by filtration. Evaporationrof the ether from the filtrate yields the desired [ii-dimethylaminoethyl p-bromobenz'hydryl ether as a light colored oil. If desired, the ether filtrate of the free base obtained above can be treated with an excess of dry hydrogen chloride in isopropanol to form the hydrochloride salt. The hydrochloride salt of the fl-dimethylaminoethyl p-bromobenzhydryl ether which separates from the solution is collected and purified by recrystallization from isopropanol; M. P. 144-5 C.-

Quaternary ammonium salts of ,6-dimethylaminoethyl p-bromobenzhydryl ether can be prepared as described in the preceding .examples. The methochloride salt is obtained as follows:

10 g. of the free base of fi-dimethylaminoethyl p-bromobenzhydryl ether is dissolved in 75 cc. of dry benzene and dry methyl chloride passed through the solution until no more solid separates. The mixture is allowed to stand for about four or five hours and the B-(p-bromobenzhydryloxy) -ethyl trimethylammonium chloride collected and purified by recrystallization from isopropanol.

Ezvwmple 4.-B-Dimethylamn0ethyl p-z'odobenzhydryl ether 25 cc. of acetyl bromide is added slowly with stirring to a solution of 62 g. of p-iodobenzhydrol in 50 cc. of benzene and after theaddition has been completed the reaction mixture is refluxed for one hour. The benzene, excess acetyl bromide and the acetic acid formed in the reaction are removed by distillation in vacuo to obtain the desired p-iodobenzhydryl bromide.

The p-iodobenzhydryl bromide prepared as described above is dissolved in about 20 cc. of xylene and the solution added to a refluxing solution of 40 cc. of S-dimethylaminoethanol in cc. of xylene. After the addition has been completed the reaction mixture is refluxed for about two hours,'cooled and treated with about 100 cc. of water. The aqueous layer is extracted once with ether and then discarded. The ether extract is added to the organic layer, the mixture washed with water and then extracted with dilute hydrochloric acid. The acidic aqueous extract is clarified by extracting it once with ether, the ether discarded and the aqueous solution made alkaline with 50% sodium hydroxide solution.

Th e-ffree' base-of fi-dimethylaminoethyl p-iodobenzhydryl ether which separates is'je'xtracted with ether, the ether extracts dried' over'potasrisopropanoleether mixtureyM. .P. 1 625- 1645"- 0.

5 g. of fi-dimethylaminoethyl D-iodobenzhydryl ether hydrochloride is dissolvedjnwater, the solution made -alkaline with sodium hydroxide solution and the free base of the fl-dimeth'ylaminoethyl p-iodobenzhydrylether which separates extracted with ether. ether extracts are dried and the ether distilled to obtain the free base as a light yellow to colorless oil.

The quaternary ammonium salts or the amino ether of this example can be prepared in the same manner as described in the preceding examples. v

.What. I claim is:

v 1. A compound of the class consisting of a free base, its quaternary ammonium salts and its acid addition salts, said free base having the formula,

wherein X represents a member selected from the group consisting of chlorine and bromine.

3. A free base of the formul oH-o-omomN CY where X is a halogen atom.

4. A quaternary ammonium salt of a free base of formula,

Where X is a halogen atom.

5. An acid addition salt of a free base of formula,

Ck Q where X is halogen atom.

6. A, hydrochloride salt of a free base of formula,

v CH-O-OHzGHzN where X is a halogen atom.

. 7 8 7. fl-Dimethylaminoethyl p=fluorobenzhydry1 Number Name Date ether hydrochloride. 7 2,427,878 Rieveschl Sept. 23, 1947 8. 13-Dimethylaminoethy1 p-bromobenzhydryl 2,437,711 Rieveschl Mar. 16, 1948 ether hydr0ch1oride.;- 2,455,949 Rieveschl Dec. 14, 1948 9. p Dimethylaminoethyl p iodobenzhydryl 5 OTHER REFERENCES ether, hydrochloride. 7 7

V GEORGE RIEVESCEHJ, JR Loew et al., J. Pharmacol, v01. 83, pages 2 120-129 (Feb. 1945). I v REFERENCES CITED Loew et al., "Proc. Soc. Exp. Biol. Med, Vol. 1 v I 58, pages 235-237 (March 1945). g%e i g g kigi are of the m Wells et.a1., J. Pharmacol. Exp. Therap, v01.

. 1 7 85,page 122 (October 1945) UNITED'sTAT-ES PATENTS Winder et aL, J. PharmacoL, v01. 87, pages 1 2;397;799 Martin Apr; 3-2,: 1946 15 2,421,714 Rieveschl June 3, 1947 

1. A COMPOUND OF THE CLASS CONSISTING OF A FREE BASE, ITS QUATERNARY AMMONIUM SALTS AND ITS ACID ADDITION SALTS, SAID FREE BASE HAVING THE FORMULA, 